Static and dynamic seals

Abstract

Described are techniques for use with a sealing member forming a static seal or a dynamic seal at a surface thereof. The sealing member has at least the surface thereof formed from one of VESPEL® SCP 5000 material or VESPEL® SCP 50094 material.

What is claimed is: 
     
       1. A sealing member forming a dynamic seal at a surface thereof, the sealing member having at least the surface thereof formed from one of an unfilled thermoset polyimide polymer or a thermoset polyimide polymer with a graphite filler, wherein the sealing member is a needle seal comprising a first portion and a second portion, said first portion having a t-shaped profile with a through hole formed therethrough, an inner surface of the through hole being the surface at which the dynamic seal is formed when the inner surface is in contact with a needle tip inserted into the through hole, wherein the first portion includes a top portion and a bottom portion, wherein said top portion has a cylindrical shape and said bottom portion is inserted into said second portion of the needle seal, wherein said through hole includes an inwardly tapered portion, wherein said second portion is formed from stainless steel. 
     
     
       2. The sealing member of  claim 1 , wherein the sealing member forms the dynamic seal in a liquid chromatography system. 
     
     
       3. The sealing member of  claim 1 , wherein the needle seal is included in an injector used to inject a sample into a liquid chromatography system. 
     
     
       4. The sealing member of  claim 1 , wherein the first portion is formed from said unfilled thermoset polyimide polymer. 
     
     
       5. The sealing member of  claim 4 , wherein a first portion of the through hole tapers inwardly with respect to an opening at a first end of the through hole into which a needle having the needle tip is inserted, and wherein a second portion of the through hole is untampered and is adjacent to the first portion of the through hole, and wherein the through hole includes another tapered portion adjacent to the second portion of the through hole, the other tapered portion forming a conical portion at a second end of the through hole opposing the first end. 
     
     
       6. The sealing member of  claim 1 , wherein said second portion is formed from a material having mechanical properties indicating that the second portion has a mechanical strength which is greater than the first portion. 
     
     
       7. The sealing member of  claim 1 , wherein the sealing member is included in an apparatus also comprising an injection port, and the sealing member is separate from the injection port. 
     
     
       8. The sealing member of  claim 1 , wherein the through hole further includes another portion having a relatively uniform diameter. 
     
     
       9. The sealing member of  claim 1 , wherein a needle having the needle tip, when inserted into the through hole, does not extend completely through the through hole when the dynamic seal is formed.